What's the point of buying a jeep wrangler (or a ferrari), when you already have a subaru? Don't they all have 4 wheels?

General purpose tools are good for most cases. And being widely available they are cheaper too. Sometimes, however, you can do a better job with something special purpose tuned to the exact task at hand, but you have to buy the special purpose tool. The question is not IF it's better the question is whether it's worth the cost to you.

here are some things malloc can't do (afaik): - different pools for different parts (threads / datastructures / etc) of your app - better control over data locality - real time / non blocking allocations (i.e. low latency audio applications) - querying remaining available memory - releasing entire pools with a single call